924T
Well-known member
After reading lazersteve's MLCC process several times, I have a few questions.
Step #1.: Is this a heated process with the 15% HCl, and if so, is it boiling as in Samuel-a's process, or would
it be at a low enough temperature to perform this step in a food-grade plastic bucket?
Step #3.: Would air bubbling/sparging instead of the H2O2 additions yield the same results in the same amount
of elapsed time, and somewhat 'self stir' the MLCC's?
Would a stirring bar in the reaction vessel assist the process?
Is the suggested slight heat slight enough that this step could be conducted in a food-grade plastic bucket?
Step #5.: What is the purity of the Pd at this stage of the process? I'm curious to know whether it's a quantum
leap to get the Pd to .9999, or just a wee bit of a jump.
Step #6.: Rather than Sodium Chlorate, could Calcium Hypochlorite used as the Chlorine source? I can get
Calcium Hypochlorite locally, at Menard's, thus saving shipping costs and avoiding the explosion
potential of Sodium Chlorate.
If the Hypochlorite will work as the Chlorine source, should I make a solution of it, or can the pellets
be added directly to the leachant?
Many thanks,
Mike
lazersteve said:Re: Problem with Pd from MLCC
I use Acid Peroxide on my MLCC's that contain Pd:
0. Test a small sample for Pd before processing, not all MLCC contain Pd.
1. Remove base metals with 15% HCl.
2. Crush (optional)
3. Cover with 32%+ HCl and heat slightly in covered dish with stirring, adding a few milliliters of 35% H2O2 as need to keep the reaction going. Stop peroxide additions when only a white powder remains in the colored solution. Don't over do the peroxide additions, you only need enough to keep a gentle fizzing going.
4. Filter the solids out until only the 100% transparent liquid remains. The solution should be an orange brown to deep burgundy colored and free of any particulate.
5. Slowly add aluminum foil in small strips with stirring to the solution. The aluminum will precipitate the Pd as a sponge. Aluminum does not precipitate nickel from solution.
6. Filter out the sponge and refine a second time using AP, this time precipitating with Sodium Chlorate (or chlorine gas) and ammonium chloride (or potassium chloride).
7. Purify the colored Pd salt as see here: Purifying Pd Salts
8. Calcine the purified colored salt or reduce with hydrazine, formic acid, or your favorite reducing agent.
9. Filter the sponge out and melt under an oxy/hydrogen flame.
You'll have a lot of work in those little buggers and a whole lot of nasty wastes, so be responsible when you go to dispose of them.
Steve
Step #1.: Is this a heated process with the 15% HCl, and if so, is it boiling as in Samuel-a's process, or would
it be at a low enough temperature to perform this step in a food-grade plastic bucket?
Step #3.: Would air bubbling/sparging instead of the H2O2 additions yield the same results in the same amount
of elapsed time, and somewhat 'self stir' the MLCC's?
Would a stirring bar in the reaction vessel assist the process?
Is the suggested slight heat slight enough that this step could be conducted in a food-grade plastic bucket?
Step #5.: What is the purity of the Pd at this stage of the process? I'm curious to know whether it's a quantum
leap to get the Pd to .9999, or just a wee bit of a jump.
Step #6.: Rather than Sodium Chlorate, could Calcium Hypochlorite used as the Chlorine source? I can get
Calcium Hypochlorite locally, at Menard's, thus saving shipping costs and avoiding the explosion
potential of Sodium Chlorate.
If the Hypochlorite will work as the Chlorine source, should I make a solution of it, or can the pellets
be added directly to the leachant?
Many thanks,
Mike